This is a quality aftermarket 40 series driver and driven pulleys. Driver has a 1" bore with 1/4" key. Driven is 7 5/8" diameter with 5/8, or 3/4" bore and 3/16" key way.Refer to the Comet 40 series belt chart to choose the correct belt. https://www...

Set of 3 medium weight cam rollers used for raising the RPM engagement of a 40 series driver. With the stock springs, your RPM engagement will be 2,200 RPM's. Pair these with the Red Springs (KD203040A) for a 2,600 RPM engagement.